pH-responsive phenol–formaldehyde resin: aggregation mechanism and plugging science.

Enhanced oil recovery research focuses on the phenol–formaldehyde resin (PFR) solution (EOR). We studied PFR's morphology and aggregation kinetics at various pH levels. A hydrated layer formed on the surface of PFR as a result of hydrogen bonding between the hydroxyl and phenolic hydroxyl groups and water molecules. We quantitatively quantified the impact of pH on the morphology and aggregation kinetics of PFR by incorporating the hydrated force into the DLVO (Derjaguin Landau Verwey Overbeek) theory. We were able to predict the situation of aggregates plugging into the reservoir by altering the size of PFR aggregates in a capillary. [ABSTRACT FROM AUTHOR]